Just my opinion..
Button last year was in easily the best car and won the championship because of the superiority of the Brawn over the rest of the field.
This year Button and Hamilton have the same car and he's getting hosed by another driver in the same car. Hamilton can make the car work when its not perfect, Button just whinges and says he can't get the feel for it. A true champion can work around an imperfect chassis as Hamilton, Rosberg, Kubica and even Sutil do on occasions where the tracks play to the cars slight strengths. Button can't seem to step up in a similar car the way Hamilton has this year. And they are both getting the same treatment by the team.
I have no affinity for Hamilton either don't get me wrong and agree Kubica is massively underrated, but Button just isn't champion material IMHO.
Last year, the Brawn was the champion, he was just the lucky guy in the right car at the right time....